Dental matrix retainer



y 1932- R. R. IMPEY ET AL v1,857,910

DENTAL MATRIX RETAINER Filed Oct. 29, 1929 INVENTOR, Faerf 73. I'm h y B y P09 ATTORNEY Patented May 10, 1932 UNITED STATES PATENT OFFICE 201mm a. mentor slur rancisco, AND RAY WHIPPLE, or MILL VALLEY,

' CALIFORNIA DENTAL MATRIX RETAINER Application filed October 29, 1929.- SerialNo. 403,288.

The present invention relates to retainer for a dental matrix, for supporting the matrix band while inserting it in and withdrawing it from the mouth and for tightening the 5 band around the tooth body withinthe mouth.

. A matrix as used in the dental arts is commonly considered as consisting of the combined band and retainer member, but for purposes of description herein, theparts are referred to separately as theband and the retainer. p

As is well. known, the purpose of avmatrix is to horizontally surround the vertical walls of one or more teeth with a band sothat a temporary improvised wall may be provided externally of the tooth. V

l-Ieretofore the matrix retainer most generally used by the dental profession and known as the 'Hiniker matrix, has consisted of a threaded shaft having a pair of cooperating blocks mounted thereon, the first or lower block mounted in station- "ary placement at a lower end of the shaft and in which the lower end of the shaft is free to rotate, said shaft not beingv threaded through this lower block, but. having at the end of the shaft a small riveted washer to prevent the lower end of the shaft from disengagement with the lower block. This low- 0 er block had mounted a pair of pins adapted to pass through a pair of openings transversely disposed adjacent each end of the I matrix band, and thereafter said pins were adapted to pass through openingsin the second block which was threadedly mounted on the shaft, so that byturning the shaft, the second or upper block was advanced toward the first or lower bloolgand thereby slidably engaging the pins, and thereafter contactpurpose of drawing the band tightly around the tooth.

Difiiculty wasencounter'ed in the use of the existing retainers, due to the fact that the upper or recipre'oable block frequently becomes unaligned with the band'pins, due to lack of guiding means, and to correct this, some recent retainers have provided a guide for the reciprocable block, said guideconsisting of a frame integrally made with the lower tamer.

block and extending parallel with the threaded shaft, and again turnably engaging the shaft adjacent the opposite end, thus providing a guiding face against which the butt face of the reciprocable block was in s'lidable contact. i

This structure, however, did not provide any guides to prevent a sufficient transverse movement of said block .to disalign the holes therein with the pins of the lower block this structure also permittedand partially caused a frictional binding of the reciprocableblock with relation to the threaded shaft a further difficulty was that since the shaft freely turned in the lower block, a small washerhad to be placed at the end of the shaft and riveted thereupon, and when the band was tightened around the'tooth, all of thestres s .had to beborne by this delicately riveted shaft end with the result that the fastening frequently broke while in the mouth of a patient, necessitating re-arrangement of the matrix-anew. This was very inconvenient because dental work is often done while a patient :1s enduring pain or is under an- I anaesthetic, and speed is the essence of success.

. Existing retainers also operate with a thread effective in one direction only, which requires twice as long to manipulate as a complementary thread effective in both directions.

The objects of this invention are tol'provide a matrix retainer wherein the blocks are guided one by the other, both longitudinally and transversely to precisely guide the bandholding pins into engagement withcooperating openings in the. opposite block; to provide a more secure and effective base toreceive the thrust of pressure when the matrix ing withthe ends of the matrix band for the band is tightened around a tooth," to provide a quickly operated retainer, and to generally improve upon the present type of matrix re-r With the foregoing and other objects in 7 view, theinv'entio'n consists, broadly, in the novel construction,- a'rrangement and formof parts of a matrix retainer whereinthe cooperating blocks are guided toward each other. in simultaneous advancement, and wherein the pressure thrust on both blocks Fig. 3 is a transverse vertical section on line 3-3 Fig, 1.. y

Referringto the drawings, 1 is an elongated threaded shaft being threaded substantially throughout its length, said threads being right hand throughout one portion, as at 2, and left hand at another portion 3, the division between direction of thread being preferably at approximately the longitudinal center 4 of the threaded portion of the shaft, said shaft having a squared end 5 at what may be called an upper end and being butted at its opposite end 6, or what may be called the'bottom end, the said butt being formed preferably integral with the shaft by axial indentation 7 forming the peripheral edges outwardly. I

Upon shaft 1, at one side of said longitudinal center 4, is threadedly mounted block 8, which has an inset cut 9 externally longitudinal of the lower portion thereof, providing shoulders 90; intermediate its top and bottom,-

in side elevation, said block 8 mounting a pair of elongated pins 10 in spacedrelative parallelism, and substantially parallel with shaft 1, said pins 10 being preferably slightly bevelled at their points 10a, adapted to receive and support a matrix band, the respective ends 12 and 13 of which have spaced openings 14 to receive said pins therethrough. 'Threadedly mounted on the shaft 1, at the other side of its longitudinal center, is a second block 15 which has an opening 16 longitudinally therethrough and an elongated longitudinal trough or channel 17 extending from its lower side substantially parallel with the shaft 1 and adapted to slidably receive and guide within said channel the inset portion 9 of the block 8 disposed below the shoulders 9a, which latter are adapted to slide upon the upper edge surface of the channel 17. This channel 17 and the complementaryportion 9 of the block'S may be'formed in any suitable shape, whereinthe channel 17 is adapted to receive and guide the block 8, but I prefer a shape arcuate in cross sect1on, as shown n the drawings, since it permlts of rounded edges wh ch are preferable in an instrument to be inserted in the mouth.

The opening 16 may be bevelled las'at 18 for the purpose of cooperating with the points 10a of the pins 10, to readily effect alignment when the blocks 8 and 15 are advanced toward each other. A socket wrench (not shown) of any suitable type is used to turnably operate the squared end 5, but such wrench of itself is not a part of this invention.

It is to be understood that the pins 10 and the opening 16, as well as the channel 17 may be optionally transferred for attachment to or as apart of either block, or that the blocks may be transposed in their respective positioning' on the shaft, as well as various changes of form, proportion, size and minor details of construction within the scope of the claims, ma be resorted to without departing from t e spirit or sacrificing any of the advantages of'the invention.

In operation, assuming the blocks 8 and 15 to be in contact at the longitudinal center 4 of the shaft 1, and the pins '10 enclosed within the opening 16, the squared end 5 is turned contraclockwise'by any suitable means, such as a socket Wrench; the threads of shaft 1 being respectively in reverse directions from the portion 4, move the blocks away from each other and thereby draw pins 10 from the openings 16 until the pin points 10a are in spaced relationship to the bevelled end 18 of the opening 16. This permits the perforatedends of the matrix band 11 to be successively mounted over the pins so that the transverse width of the band is transverse the pins. The band is then positioned loosely around the vertical walls of a tooth 19 in a well known manner, and the band is constricted to tight engagement with said vertical tooth walls by turning the shaft 1 clockwise, thus advancingthe respective blocks 8 and 15 toward each other and into contact with the respective ends of band 11, and drawing the pins 10 into the opening '16. It is apparent that as the band is thus tightly drawn around the tooth walls, the

" band will form an improvised temporary external wall around a cavity 20, permitting a filler material to be placed therein and packed by hammering or other means, without dislodgment or breaking of the filler material. WVhen the dental operation is completed, it is obvious that the band may be removed by reverse turning of shaft 1.

' The butting of the shaft at 6 by means of the indentation 7, acts to prevent the block '8 from being threadedly moved beyond the shaft end. It is not necessary to have a similar stop at the opposite end of the shaft 1, since, when block 8 can move no further on the threads, block 15 can move no further, because both move simultaneously by the reverse direction of the threads. reason, it is advisable that the division of direction of threadsjshould be at substantially the longitudinal center of the shaft 1. By means of the inter-engagement of the block 8 with channel 17 and the contacting For that guide formed by the edges 17a of said channel with the shoulders 9a of block 8, the blocks are alignedly guided each by the other and both shaft and block are securely positioned against sidewise movement or turning, the blocks being longitudinally aligned by shaft 1, and thereby maintaining the alignment of the pins 10 with the opening 16. The blocks being moved in opposite directions simultaneously by the right and left thread of the shaft, the relation of their movement either forward or rearward is just twice as fast as though one block were stationary and the movement of the cooperating block were on a one direction thread.

Having thus described the invention, what we claim and desire to secure by Letters Patent is 1. A matrix band retainer comprising an aligned axially rotatable shaft, said shaft threaded right hand at one portion thereof and threaded left hand at another portion thereof, a block threadedly mounted on each of said contrary threaded portions of said shaft and provided with opposed faces, said blocks adapted to reciprocate simultaneously in oppositely defined paths upon axial rotation of the shaft, one of said blocks having associated therewith an elongated channel portion adapted to guide said blocks in alignment with relation to each other, pins mounted on one of said blocks adapted to slidably receive and support the ends of a looped matrix band, openings in the other block to releasably engage said pins, the path of movement of said blocks on said shaft being of greater length than the length of the pins. 1

2. A matrix band retainer comprising an axially rotatable shaft threaded right hand at one portion and threaded left hand at another portion, a block threadedly mounted on each of the contrarily threaded portions of the shaft, said blocks having opposed faces, means proJecting from the face of one of said blocks adapted for mounting the respective ends of a matrix band between the opposing faces of said blocks, one of said blocks having an elongated grooved member mounted thereon, adapted slidably to receive and guide the other of said blocks in the reciprocable movement thereof, and said rotatable shaft being positioned between said grooved member and the means to mount the matrix band.

3. A matrix band retainer comprising a shaft, said shaft threaded right hand at one portion thereof and threaded left hand at another portion thereof, a block threadedly mounted on each of said contrary threaded portions of said shaft, mounting means on one of said blocks adapted to mount the respective ends of a matrix hand between opposing faces of said blocks, the other block being provided with openings to slidably engage said mounting means, and an elonlib 

